We divide 413083 by 81
The aim is to understand the frequency of 81 in 413083.

On to step 1:
4 divided by 81 is 0 with a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Include the next digit (1) from the dividend after 4, then repeat: 41 / 81

Moving on to step 2:
81 goes into 41 0 times with a remainder of 41.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 41, we get 41.
Grab the next digit (3) from the dividend, add it to 41, then carry on: 413 / 81

Going ahead to step 3:
81 can be fit into 413 5 times, resulting in a remainder of 8.
Put 5 as the next digit of the answer. 
Result so far: 5.0
Deduct 405 from 413 and we're left with 8.
Append the next digit (0) from the dividend to 8 and continue with: 80 / 81

Moving on to step 4:
When dividing 80 by 81, we get 0 with a remainder of 80.
The next digit of our result is 0. 
Result so far: 50.0
The remainder is 80 after subtracting 0 from 80.
Bring next digit (8) of the dividend behind the 80 and repeat the process: 808 / 81

Let's proceed to step 5:
When dividing 808 by 81, we get 9 with a remainder of 79.
Write down 9 as next digit of the result. 
Result so far: 509.0
If we take 729 away from 808, we end up with 79.
Include the next digit (3) from the dividend after 79, then repeat: 793 / 81

Going ahead to step 6:
81 goes into 793 9 times with a remainder of 64.
Use 9 as the next digit of our solution. 
Result so far: 5099.0
The remainder is 64 after subtracting 729 from 793.
Since there are no more digits in the dividend, we add a zero to the remainder making it 640, and continue the process.

Advancing to step 7:
81 can be fit into 640 7 times, resulting in a remainder of 73.
Use 7 as the next digit of our solution. 
Result so far: 5099.7
If we subtract 567 from 640, we get 73.
Since there are no more digits in the dividend, we add a zero to the remainder making it 730, and continue the process.

Let's proceed to step 8:
81 can be fit into 730 9 times, resulting in a remainder of 1.
Use 9 as the next digit of our solution. 
Result so far: 5099.79
Deduct 729 from 730 and we're left with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Going ahead to step 9:
If we divide 10 by 81, we get 0 and a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 5099.79
If we subtract 0 from 10, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 10:
The number 81 fits into 100 1 times, leaving a remainder of 19.
Record the quotient 1 as the next digit in the result. 
Result so far: 5099.7901
Deduct 81 from 100 and we're left with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Advancing to step 11:
81 can be fit into 190 2 times, resulting in a remainder of 28.
Record the quotient 2 as the next digit in the result. 
Result so far: 5099.79012
Subtracting 162 from 190 leaves us with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Step 12:
If we divide 280 by 81, we get 3 and a remainder of 37.
The next digit of our result is 3. 
Result so far: 5099.790123
If we subtract 243 from 280, we get 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

Moving on to step 13:
The number 81 fits into 370 4 times, leaving a remainder of 46.
The number 4 becomes the next digit in our result. 
Result so far: 5099.7901234
Subtract 324 from 370 to get 46.
Since there are no more digits in the dividend, we add a zero to the remainder making it 460, and continue the process.

Advancing to step 14:
The number 81 fits into 460 5 times, leaving a remainder of 55.
The number 5 becomes the next digit in our result. 
Result so far: 5099.79012345
If we subtract 405 from 460, we get 55.
Since there are no more digits in the dividend, we add a zero to the remainder making it 550, and continue the process.

The final outcome is 5099.79012345, with a leftover of 5.5e-08.